1. Field of the Description
The present description relates, in general, to creating realistic skin for robots or for use with robotics or other applications in which skin or similar coverings are applied (e.g., robotics used to simulate movement of a human's or a character's face, hands, or the like), and, more particularly, to a skin or artificial skin system with a flexible joint adapted for joining two sides of a seam in the skin and to a method of forming such a joint in a skin.
2. Relevant Background
Durable materials that are often also flexible and elastic such as plastics and rubbers are used in many applications to create coverings or skins that are applied over an internal physical support structure or skeleton. For example, artificial skins or skin systems are used to create realistic models of humans, animals, and characters, and, when combined with robotics, such models may accurately simulate live beings.
Robotics involves the design and use of robots to provide programmable actuators or drivers to perform tasks without human intervention, and there have been significant demands for robotic devices (or robots as these terms may be used interchangeably) that simulate humans, animals, and other living beings or characters. These robotic characters are relied upon heavily in the entertainment industry to provide special effects for movies and television and to provide robots for use in shows and displays in amusement or theme parks. For example, robotics may be used to provide a character in a theme park ride or show that repeats a particular set of movements or actions (e.g., programmed tasks) based on the presence of guests or a ride vehicle or another triggering event.
It is likely that the interest in robotics will continue to expand in the coining years, and a growing area of interest is how to provide robots that appear more realistic. Many robotics companies have focused on creating robots with software, processing hardware, and mechanical actuators or drivers that allow the robots to behave more like the natural creature that is being simulated. Much work has been done to create robots that can move and even behave similar to humans such as by manipulating objects with mechanical assemblies that behave like hands configured to be human-like. Significant effort has also been directed to providing robots with realistic facial animation such as having a robot open and close its mouth to provide lip synchronization with output audio (e.g., with speech) and by providing particular facial movements including eye movement such as frowning, smiling, and the like.
While many advances have been made in realistically simulating the physical movement and facial movement of a character, problems with maintaining a realistic or desired movement or facial animation still occur when the robotics (e.g., internal components of a robot including mechanical/structural portions as well as software, hardware, power systems, and the like) are covered with a skin or skin system, and the realism of the robotic figure or character may be furthered or hindered by the movements of the skin. For example, a robot used to simulate a particular creature would be covered with skin or a covering assembly to imitate the natural or desired covering for the creature such as skin and fur/hair for many creatures, clothes for some creatures such as humans or characters (e.g., characters from animated films or television or puppets), or more fanciful covering system such as a metallic suit or any other desired covering.
In simulating humans or human-like characters, the robotics are typically covered in a skin that is fabricated of flexible material to move naturally with the underlying robotics. The skin may be formed of a rubber material or a silicone that is attached or anchored to the mechanical actuators or drivers of the robotic system, and the skin is configured to have an outward appearance similar to the character or creature being simulated by the robot. For example, the facial skins can be formed so as to have an uncanny resemblance to the character (or person) they are imitating, but often this resemblance ends when the attached robotics begin animating the face. The skin typically is of a single material with one set of physical characteristics such as hardness, flexibility, and the like.
To initially assemble and then later maintain the robotics, the skin or skin system typically will include at least one seam where two portions or sides of the skin are joined together. In providing such a joint in the skin, it is desirable for the joint to be durable and lasting, for the joint to allow repeated use (e.g., opening and closing/mating of the joint) to allow the skin to be applied and removed numerous times, and for the joint to facilitate or at least not hinder realistic movement of the nearby skin or covered robotic components. For example, in a human-like character, a seam that has to be joined may be provided on the back of the neck so as to allow application and removal of a skin system over a robotic head. The robotics may require periodic maintenance such that the skin may be removed numerous times over the life of the robotic character. However, it is also very important for the joint on the neck to be formed so as to limit any interference or binding of the overall skin system that may be seen in the face, ears, top of the head, or front portion of the neck as this may spoil or reduce the realistic movement of the skin.
Presently, a number of join techniques are used in fabricating skin systems for robotics and other applications. One approach is to bond the two sides of the seam together such as by applying adhesive to two flat abutting sides after the skin is positioned over the robotic assembly or feature. Bonding can provide a relatively flexible joint, but it is typically undesirable as it can come apart over time and, more significantly, does not allow for opening and closing for access to the covered components. Stitching is sometimes used for joining a seam in skin, and a stitched seam provides some amount of stretching and twisting. But, stitched seams are typically not very durable as the stitching material quickly tears at the stitching holes with movement of the underlying robotics, causing the joint to fail over time.
In many skin systems, a conventional zipper is bonded into the seam during the molding process for a skin system, and then after application of the skin system, the zipper is used to open and close the seam of the skin system (such as for the back of a head or a wrist of a human robotic character). Zippers provide a strong and reusable joint. However, there are a number of problems with the use of zippers in many applications where realistic skin movement is required or desired. Fabrication can be time-consuming and difficult as the fabricator has to fully clean up the zipper to remove all skin material from its teeth and working parts to allow the zipper to work properly. The zipper is a foreign material or body that has to be molded into the skin, which is not sympathetic to the movement of the adjoining flexible skin material. As a result, the zipper may tend to tear out of the seam over time and repeated use. Further, zippers are a single body or member that tends to move as a unit such that the skin in the area near to the zipper may move in an unnatural or undesirable manner, e.g., a zipper in the back of a neck may move as a block with such movements being propagated to the front neck skin and facial features causing them to twist or pull in a non-realistic manner. Zippers typically are not flexible or pliable (e.g., readily able to stretch or “stretchy”) so that, in addition to moving as a unit, the zippers can cause unnatural looking movement in adjoining areas of the skin.
Hence, there remains a need for improved methods for fabricating skin systems or simply “skins” for robotics and other applications that involve covering a support structure with a covering or skin. Preferably such methods would be inexpensive and relatively simple to carry out and would provide a joint for a seam in the skin that is flexible (e.g., move more naturally with the adjoining skin material) and also durable.